Apparatus for blue-printing.



No. 687,272. Patented Nov. 26, |90l.

E. SCHILDHAUER.

APPARATUS Fon BLUE PRINTING.

. (Applicationled 1hr. 11, 1901.) (No Model.) 2 Sheets-Sheet I.

Patented Nov. 26, 190|. E. SCHILDHAUER.

APPARATUS FOR BLUE PRINTING.

(Application Blad Mar. 11, 1901.)

(No Model.)

2 Sheets-Sheet 2.

111111111111111.will/Irl 1l/1111111011111 5o frame.

UNITED STATES PATENT OEEICE.

EDWARD SCI-IILDHAUER, OF CHICAGO, ILLINOIS, ASSIGN OR TO EUGENE DIETZGEN COMPANY, A CORPORATION OF ILLINOIS.

APPARATUS FOR BLUE-PRINTING.

SPECIFICATION forming part of Letters Patent No. 687,272, dated November 26, 1901.

Application filed March 11, 1901. Serial No. 50,677. (No model.)

To all whm t may concern:

Be it known that I, EDWARD SCHILDHAUER, a citizen of the United States, residing in the city of Chicago, county of Cook, and State of Illinois, have invented a new and useful Improvement in Apparatus for Blue-Printing, 'of which the following is a specification.

My invention relates to apparatus for reproducing drawings, tracings, and the like by the process commonlyT known as blue-printing, in which sensitized paper is exposed to light in contact with the sheet or plate from which the reproduction is to be made.

It is well known that in the usual procedure the copy sheet or plate isplaced between the sensitized sheet and a glass plate, the said sheets being pressed against the glass and subsequently exposed to rays of light entering through said glass. For the purpose of excluding light from behind and also for the purpose of edecting amore evenly distributed pressure 0f the sensitized sheet against the copy sheet or plate a pad of felt or other fabric is placed behind and forced against the said sensitized sheet, it being well understood that it is a great desideratum to maintain the said sheets in close contact with each other.

The objects of my invention are, first, to provide an apparatus having an air-tight frame from which the air may be quickly and leasily exhausted, thereby permitting the weight of the outside atmosphere to act upon the diaphragm of the frame for the purpose vof maintaining close contact of the sheets, and, second, to so construct the frame and diaphragm that articial lightfor example, from an arc-lamp--may be used to advantage both with regard to convenience and economy.

It is also my object to provide certain details more specifically set forth hereinafter.

I attain these objects by the mechanism shown in the accompanying drawings, in which- Figure l is a perspective view of the complete apparatus.y Fig. 2 is a plan view of the printing-frame. Fig. 3 is a detail view, in vertical section, showing the arrangement of the parts at the upper rim of the printing- Fig. 4 is a plan view in detail of the parts as in Fig. 3. Fig. 5 is a plan view in detail of a portion of the upper rim of the printing-frame, showing construction of the door-hinges. Fig. 6 is a detail view in elevation, showing the mechanism for locking the swinging diaphragm-doors.

Similar characters refer to similar parts throughout the several views.

The printing-frame comprises the upper and lower rings a and b, respectively connected and supported by the uprights c and d. The said rings and uprights constitute frameworks wherein are mounted the glass plates e e, said plates being let into said rings and uprights in such a manner as to form airtight joints therewith. Thus in the particular construction shown the main constituent part of the printing-frame consists of two half-cylinders of glass set in a preferably metallic framework. The said upright c at the rear of the frame forms a point of attachment for the hingesffof the diaphragm-doorsg g, as shown in detail in Fig. 5. Said diaphragmdoors each consist of the uprights h 71, and t' t', connected by the top membersjj and bottom members 7c 7c, which together constitute frameworks similar in conguration and dimensions to the frameworks wherein the glass plates e e are mounted. The uprights h are secured to the hinges f above mentioned, so that said doors g may swing outwardly about the upright c as an axis. Extending across the area bounded by said door members h, ,j, and 7c are the diaphragme m m, which make air-tight connection therewith, preferably upon the inner surfaces thereof, and consist of sheets of rubber, rubber-covered canvas, or other fabric which is flexible and at the same time impervious to ir. In order to insure air-tight connection between the members Ct and j and b and 7c, respectively, when said doors g are closed and to insure such connection between the upright members c and h and d and t', respectively, there is provided a gasket or washer n, which consists, preferably, of a strip of rubber or rubber-mixed fabric placed between the opposing surfaces and desirably secured to such of the above-mentioned members as are stationary.

A convenient form of lock for forcing the doors g g vclosely into contact with the stationary portions of the frame is indicated in Figs. 1, 2, and 6, the upright d having the shafts o o supported thereon, so as to rotate about a vertical axis.. Said shaft is provided with eccentric portions adapted to rotate within collars p, formedupon the hasps 0. Said hasps have at their free extremities heads s. The members t' of the diaphragmdoors have slots t, adapted to receive the shanks of said hasps fr. The shafts 0 are rotated by means of a handle u, and the parts `are so constructed that when the door g is closed and the shank of the hasp r placed within the slot t the rotation of said shaft 0 will by means of its eccentric portion force said hasp against the upright il, thereby effecting a tight closure of said door g.

Suspended by means of the hooks o or in any other suitable manner is a pad w, consisting, preferably, of felt or carpet and occupying a position between the glass e and the diaphragm m, as shown in Fig. 3. The purpose of said pad is to distribute the pressure of said diaphragm in the manner above referred to.

From the construction of the printingframe as described it is evident that when the diaphragm-doors are closed an air-tight chamber is formed between the diaphragm m and glass e. When the air is exhausted or partially exhausted from said chamber, the weight of the outside atmosphere acting upon said diaphragm causes the latter to press toward the glass e. The air-duct a, formed in the ring a, affords an outlet for the air from said chamber, as shown in detail in Fig. 3. Said duct is connected with the vacuum-tank 3,/ by means of the piping e, said piping being provided with valves 1. Said tank is desirably provided with a gage 2 and is connected with the air-pump 3 by means of the hose or piping 4. The specific means for exhausting air from said tank y is immaterial, but for illustration I have shown said pump 3 pivotally supported upon the bearings 5 5, the piston-rod 6 being connected to the crank 7 upon the shaft 8. Said shaft is mounted in the bearings 9 9 and is rotated by the gear 10, driven by the pinion 11. Said pinion is driven by means of the motor 12. In the present instance the light for printing is supplied by the lamp 13, suspended from the revolving barrel 14, concentric with and controlled by the sheave l5. Said sheave is mounted in the bracket 16, preferably secured to the ring a of the printing-frame. A motor 17, also on said bracket, is connected to said sheave 15 for rotating the saine. The lamp 13 is so suspended as to hang centrally in the printing -frame, and the operation of said motor causes the raising and lowering of said lamp.

In operation one or both of the doors g are thrown open and the sensitized paper,together with the drawing or sheet to be reproduced, is placed between the pad w and the glass plate e. The door is then closed and brought firmly into place against the main portion of the frame by means of the locking devices described,an air-tight chamber being thereby formed between the glass e and the diaphragm an. By means of the pump 3 air has been previously removed from the vacuum-tank fy, the valves 1 in the meantime having been closed. After the doors g have been firmly closed the valves are opened, permitting the air confined within the frame to escapeinto the vacuum-tank y. As the vacuum is already formed in the tank f2 the air quickly rushes out of the prin tin g-f rame,a nd the atmospheric air pressing upon the outer surface of the diaphragm causes the sensitized paper and the tracing to be firmly pressed at all points against the glass plate c. Motor 1.7 is then set in motion to raise and lower the lamp 13 within the cylindric printingframe until the time of exposure to the light of the lamp 13 has beenA sufficient. The valves 1 are then closed and the doors g are opened, thereby affording access to the contents of the frame for removing the same.

It will be understood that the chief advanftage in employing a vacuum-tank is that the air may be quickly exhausted from the printA ing-frame and also that a reasonably constant vacuum may be maintained without continuous use of the pump. On account of the joints and imperfect contact between the reciprocating parts of the pump there would he a leakage if the pump were directly connected to the printing-frame and a continuous action of the pump would be necessary during printing. In my apparatus the air may be exhausted from the tank and the connection between' the tank and the pump subsequently shut off. Under these latter conditions by employing 'a tank of sufficient size a slight leakage in the printing-frame would have practically no effect upon the vacuum-gage pressure.

That I claim as new, and desire to secure by Letters Patent, is-

1, In a photographic-printing apparatus, the combination of a plurality of cylindrical plates of glass, frame-pieces bordering each of said plates of glass and making air-tight connection therewith, said frame-pieces and glass plates forming an upright cylinder; door-frames hinged to said cylinder, an airproof diaphragm extending across each of said door-frames, means for making air-tight connection between said diaphragm and the cylinder-frame, a vacuum-tank, and connections between said tank and the space bctween said diaphragm and said glass plate for exhausting the air from said space.

2. In a photographicprinting apparatus, the combination of a plurality of cylindrical plates of glass, frame-pieces bordering each of said plates and making airtight connection therewith, said frame-pieces and glass plates forming an upright cylinder; doorframes hinged. to said cylinder, an air-proof diaphragm extending across each of said. door ICO IIO

frames, means for making air-tight connections between said diaphragm and the cylinder-frame, a vacuum-tank, a noncollapsi ble duct formed in one of said frame-pieces whereby air may be exhausted from between said diaphragms and said glass plates after said doors are closed, and pipe connections between said tank and said duct.

In a photographic -prnting apparatus, the combination of a plurality of cylindrical plates of glass and frame-pieces bordering each of said plates thereby forming an upright cylinder; air-proof diaphragms9 frames for said diaphragme, hinged to said cylinder and forming diaphragm-doors; rubber gaskets adapted to come between the corresponding parts of the door-frames and cylinders frames for making air-tight contact between the parts; means for exhausting air from between said diaphragms and said glass plates;

,shafts revolubly mounted on the stationary for making air-tight connections between said doorframes and the stationary portions'of the framea EDWARD SCI-IILDHAUER Witnesses:

ELI BRANDS, ARTHUR Cox. 

